Serials were popular forms of entertainment in the pre-television era, providing a consistent and reliable audience for theaters. They began even in the silent era, primarily as novelty films. The Hazards of Helen (1914–1917), with 119 episodes of one reel each, is sometimes seen as the first serial with Western elements, although it does not run a continuous, unbroken storyline. Serials especially came to prominence in the 1930s and 1940s and were often directed at youth audiences. Aprototype for all serials might be Gene Autry’s first film, The Phantom Empire(1935), an early science-fiction Western of 12 episodes. Autry discovers the underground kingdom of Murania and gets involved in fantastical sequences involving robots, death rays, and radio broadcasts—all the while trying to get back to the ranch to air his weekly radio show, which is in danger of being taken off the air. Each episode ends with the obvious death or near death of Autry or the two youngsters who share his adventures. However, the first few minutes of the subsequent episode would backtrack long enough to show how the singing cowboy was able to escape at the last possible second. Many serials were in later years edited for release in one feature. Thus The Phantom Empire became the de-serialized Men with Steel Facesin 1940, reducing the running time from 245 minutes to 70 minutes.
Historical Dictionary of Westerns in Cinema. Paul Varner. 2012.